Css won't update my cutom function's styles

I created a custom function inside my child theme folder. I have a css also inside the same childtheme folder.
Problem is when I update the CSS, it does not take changes on my created function’s styles!
Here an example:

The Function Sample
[code title=”function”]
add_shortcode(‘sample’, ‘func’);
function func(){
return ‘<div class=”csssample”>’ . Sample. ‘</div>’;
}
[/code]
The CSS Sample
[code title=”css”]
.csssample{
displa:block;
color:red;
font:14px;
}
[/code]
Any reason why?